X5 Front differential

[mig25]

I recently bought a 2003 X5 3.0 i, I am working to catch up with all the maintenance. Hence I am posting about plugs etc on here.
I will replace the front differential, there was a dent on the seal housing, the differential ran long time with no oil.
It burned out, makes all kinds of horrible noises even after I refilled it and replaced the seal.
Removing the front differential does not seem to be such a big deal, although time consuming. Has anybody done that job?
My only concern is removing the motor mount, I believe I will have to replace some sort of O ring where the differential attaches to the motor.
Any tips or advises?
Thank you.